Apparatus for storing the state of fluidic devices



Sept. 8,1970 6. c. WESTERN-PICK, 2

- 'APPARATUS FOR STORING THE STATE OF FLU'IDIC DEVICES Filed Jan. 14,1969 US. Cl. 137552.5 6 Claims ABSTRACT OF THE DISCLOSURE A storageelement for fluidic circuits comprises a bistable valve element which inone of its stable positions allows the passage of fluid through a ductand which by application of fluid pressure to one side is moved from thesaid one stable position to the other and by application of fluidpressure to the other side is returned from said other to said onestable position. Preferably the valve element is made of permanentlymagnetised material and is movable between two magnetisable plates so asto magnetically adhere to one plate in one end position and to the otherplate in the other end position. Alternatively the valve element may beof a soft magnetic material and move between two permanently magnetisedpole pieces, preferably between the north and south pole respectively ofa permanently magnetised circuit.

This invention relates to fluidic devices and has for an object toprovide apparatus, hereinafter called a fluidic memory device, whichpermits the state of a fluidic device to be stored so as to be readableby fluid flow for reinsertion into other fluidic devices. A morespecific object is to provide a fluidic memory device as thus defined inwhich the thus stored state of the device is unaffected by temporaryfailure of a fluid supply.

According to the present invention the memory device comprises abistable valve movable, under pressure supplied from a point in fluidicsystem to a control inlet of the device, from an A position to a Bposition, and restorable to the A position by application of pressure toanother control inlet of the device, movement of the valve from the Aposition to the B position being arranged to change the condition of afluid read passage from one to the other of an open and a closedcondition, While return of the valve to A position is arrangedconversely to return said read passage to said one condition.

Preferably the valve comprises a plug slidable in a cylindrical boreunder pressure applied to either end of the bore, the valve plug havingport means in its circumference which in one but not in the other ofsaid A and B positions of the plug co-operates with the read passage toallow flow through the read passage. A convenient form of bistable valvecomprises a valve plug which incorporates a permanent magnet and ismovable in a bore of a non-magnetic body between two end plates of softmagnetic material, so that the valve plug will in its A and B positionsrespectively adhere by magnetic forces to one or the other end plate, awrite line being provided for applying pressure to the bore at one endof the valve plug and a wipe line being arranged to communicatesimilarly with the bore at the other end of the valve plug,

the plug having an annular groove in its circumference at anintermediate point of its length, and a read line passage being arrangedto intersect the bore in which the plug operates at a point of the boreat which in one end position of the plug the said annular groove willestablish intercommunication between the two points of penetration ofthe read-line passage with the plug-containing bore,

United States Patent ice while in the other end position of the plug theread-line passage is blocked by the plug.

The invention can be adapted for use in a two-dimensional matrix systemby arranging that a write line, hereinafter called Y-line, common to anumber of memory valves, is connected to each of said valves through aport controlled by a primary valve, which is of a monostable type andwhich is arranged to keep the connection to said Y-line close at alltimes unless pressure is simultaneously applied to the primary valvethrough a further write line, hereinafter called X-line, which is commonto said valve and one or more other valves controlled from differentY-lines, to displace the primary valve from its stable position to anoperative position in which the Y-line is open, thus ensuring that thesecondary valve, controlled by the Y-line, will only be moved from its Aposition to its B position if pressure is applied simultaneously to boththe X- and Y-lines associated with the said secondary valve. Thispermits a number of secondary valves to be arranged in a two-dimensionalmatrix in which sets of valves all attached to an X-line common to suchset of valves may be respectively arranged along parallel lines, whichare intersected by transverse lines each corresponding to valvesattached to a common Y-line.

The invention will now be described in more detail with reference toexamples illustrated in the accompanying drawing, in which FIG. 1 is asectional elevation, taken through the axis of the valve plug, of oneform of bistable memory valve according to the invention and FIG. 2 is adiagrammatic perspective view illustrating part of a two-dimensionalmatrix with valves of the kind illustrated in FIG. 1 constituting thesecondary valves, and monostable spring-loaded valves constituting theprimary valves.

Referring now first to FIG. 1, the memory device comprises a slab 1 ofnon-magnetic material, which may be a suitable plastics material, andwhich is perforated by a number of parallel bores 2, of which only oneis shown. In each bore 2. a plug 3 of high-coercivity or hard magneticmaterial, for example hard carbon steel, is arranged for longitudinalsliding movement. The plug 3' is of the spool type, having twolarge-diameter portions or lands 4 which are spaced from each other by asmall-diameter portion 5 so as to form a circumferential annular port orgroove 6 surrounding the small-diameter portion 5 between the two endportions or lands 4. The slab 1 is sandwiched between two plates 7 and 8of loW-coercivity or sof magnetisable material, for example of mildsteel, and the plug 3 is permanently magnetised in its longitudinaldirection so that when in contact with either of the plates 7 and :8 itwill be retained in that position by magnetic forces. Each of the plates7 and 8 is perforated at the end of each bore 2, as shown at 9 and 10respectively, and these perforations are continued by pressurisingpassages 11 and 12 respectively, which in the illustrated embodiment areprovided in covering layers 13 and 14 applied respectively to the outerside of each of the plates 7 and 8; furthermore two aligned passages 15,16 are provided for each bore in the slab 1, and penetrate the bore '2at two diametrically arranged points, so that, when the plug 3 is in theillustrated position, which may be referred to as the B position, and inwhich the plug is applied to the magnetic plate 8 shown in the drawingat the lower end of the bore, the two passages 15 and 16 are in freecommunication with each other through the annular groove or port 6 ofthe plug 3. When the plug is moved from this B position into the Aposition, in which it is in contact with the other magnetic plate 7,communication between the passages .15 and 16 is cut by one of the lands4 of the valve plug 3.

In order to use the valve plug as a memory element, the line 11 may beused as a write line and the line 12 as a wipe line, which latter ispreferably common to all the plugs 3 of a matrix. It will be readilyappreciated that when a wipe pulse of pressure is applied to line 12,all the plugs 3 of the matrix which are in the illustrated B positionwill move to their respective A position in which the plug is in contactwith the magnetic plate 7 shown at the upper plate in the drawing,cutting communication between the read-line passages 15 and 16, whilethese plugs already in their A position will be held in that position.When a write pulse is then applied to an individual plug 3 byapplication of pressure to its write line 11, this plug will move fromits A position to its illustrated B position, in which it will stay, dueto its magnetic adhesion to the plate 8, until a further wipe pulse isapplied through line 12. The existence of this B position state can benon-destructively ascertained at any time by applying pressure to oneend 15 of the read line, which in this case will cause a flow throughthe read lines 15, 16. This flow may itself be utilised in a fluidicapparatus.

FIG. 2 illustrates an arrangement in which, in order to allow arelatively large number of memory-valve plugs 3 to be controlled by arelatively small number of control lines, the operation of each valveplug is made dependent on the simultaneous presence of a pulse in bothan X-line and a Y-line, in a manner similar to that commonly employed inelectro-magnetic memory matrices of electronic computers. In order toachieve this, each valve plug 3 is operated as a secondary valve whichis operable by the application of pressure to its write line 11, whichmay be referred to as a Y-line and be common to a number of memoryvalves, only when a primary valve which is also associated with theindividual memory valve and may be common to it and a number of othermemory valves respectively included in different Y-lines, and which isnormally held in its closed position by a spring 19, is opened by thesimultaneous application of pressure to its valve plug 18 from an X-line20.

It will be readily appreciated that the invention is not limited to allthe details of the examples described with reference to the accompanyingdrawing. Thus while the primary valves in FIG. 2 have been described asrendered monostable by the use of a spring, the primary valves mayalternatively be magnetically biased, in which case their constructionmay be similar to that of the valves described with reference to FIG. 1,except that the magnetic plate 8, which in the valve of FIG. 1 tends tomaintain the valve in its operative position, is omitted or renderedinoperative by an aperture of sufficient magnitude. Conversely thememory valves may be rendered bistable in a manner different from thatdescribed with reference to FIG. 1, one possible modification consistingin the use of soft magnetic plugs in co-operation with suitablypolarised end plates or end members. Furthermore the primary valves maybe replaced by the action of, for example, a purely fluidic AND gate.

What I claim is:

1. A fluidic memory device which comprises a read passage, a valvemovable from an A position to a B position and vice versa therebychanging the condition of said read passage from one to the other of aclosed and an open position, the device having a first and a secondfluidpressure inlet so arranged that application of pressure to saidfirst or said second inlet acts to move the valve respectively from theA position to the B position or from the B position to the A position,and bias means continuously operative, independently of fluid action, toexert, When the valve is in the A position, a bias force opposingmovement of the valve towards the B position, and when the valve is inthe B position, a bias force opposing movement of the valve towards theA position.

2. A fluidic memory device as claimed in claim 1, wherein the bias meansinclude a permanently energised magnetic circuit so arranged as to havemaxima of its magnetic flux at each of the A and B positions of thevalve.

3. A device as claimed in claim 1, comprising a body having acylindrical bore closed at each end and two readpassage portscommunicating with said cylindrical bore between the two ends thereof,the read passage being made in two parts respectively terminating atsaid ports, the valve being constructed as a plug slidable in saidcylindrical bore, said first and second inlet being connected to the twoends of said bore respectively, and the valve plug having port means inits circumference which in one, but not in the other, of said A and Bpositions of the plug co-operate with said read-passage ports to allowflow through the read passage.

4. A device as claimed in claim 1, which includes a body of non-magneticmaterial having a bore and two end plates of soft magnetic materialclosing the two ends of the bore, the valve being constituted by a valveplug which incorporates a permanent magnet so that the valve plug ismovable along the bore between two end positions respectivelyconstituting the A and B positions, in each of which the plug willadhere by magnetic forces to one or the other end plate, the devicefurther including a write line extending from the first inlet to one endof the bore and a wipe line extending from said second inlet to theother end of the bore, the plug having an annular groove in itscircumference at an intermediate point of its length, and a read-linewhich includes a passage so arranged in the non-magnetic body as tointersect the bore at a point at which in one end position of the plugsaid annular groove will establish continuity of said read-line passagewhile in the other end position of the plug the read-line passage isblocked by the plug.

5. A fluidic memory system comprising a plurality of devices each asclaimed in claim 1, a plurality of write lines, hereinafter calledY-lines, each common to the valves of a number of said devices, aplurality of primary valves respectively associated with each saiddevice and each having a port which when open connects said write lineto the valve of the device in question, each primary valve being of suchmonostable construction as to be biased to keep the connection to saidY-line closed and operable by fluid pressure against such bias to opensuch connection, a plurality of further write lines, hereinafter calledX-lines, each common to two or more valves controlled from differentY-lines and connected to the primary valve associated with each of thesaid two or more valves in such manner as to displace the primary valvefrom its stable position when pressure is applied to said X-line.

6. A fluidic memory system comprising a plurality of devices, each asclaimed in claim 1, a plurality of AND gates each associated with one ofthe devices, a plurality of write-lines hereinafter called Y-lines, eachcommon to a number of memory devices and connected to each of saiddevices through one of said AND gates, and a number of furtherwrite-lines, hereinafter X-lines, each common to two or more valvescontrolled from different Y-lines and connected to the AND gateassociated with said valves, each AND gate being arranged to renderfluid supply to its associated Y-line operative upon the valve of thedevice when and only when the X-line associated with the same AND gateis supplied with fluid at the same tlme.

References Cited UNITED STATES PATENTS 3,057,551 10/1962 Etter 251-367XR HENRY T. KLINKSIEK, Primary Examiner US. Cl. X.R. 137-608; 251-63,65, 367

